Hey there TT,So i recently bought a 2004 wr450. Heap of extras, it was a good buy. I had been riding it almost non-stop for the past week until it had started playing up.It surges at low rpm, like in first gear. Idles rougher and more uneven than when i bought it and on occasion it backfires...no big backfires just more of a loud pop at the exhaust. There is also a more noticeable decel pop, which i wasn't worried about. Before all this it ran like it should and had none of these symptoms.After pulling the carb off and cleaning and trying different needle clip settings i cant figure out where i went wrong. The clip was 3 from top when i got it and i ave since tried one grove either side of that, with no luck. The other issue i have is the fuel screw (underside of carby)....i had removed that (mistake!) and im not sure where the screw needs to be set. It is currently at 1 1/2 turns out.If it helps, i'm in Australia and at sea level.Thank you in advance as i've looked everywhere for answers but i cant sort this out!!